package net.starschema.clouddb.initializer;

import java.io.File;  
import java.util.Hashtable;  
import java.util.Enumeration;  
import javax.swing.filechooser.*;  
/** 
 * A convenience implementation of FileFilter that filters out 
 * all files except for those type extensions that it knows about. 
 * 
 * Extensions are of the type ".foo", which is typically found on 
 * Windows and Unix boxes, but not on Macinthosh. Case is ignored. 
 * 
 * Example - create a new filter that filerts out all files 
 * but gif and jpg image files: 
 * 
 *     JFileChooser chooser = new JFileChooser(); 
 *     ExampleFileFilter filter = new ExampleFileFilter( 
 *                   new String{"gif", "jpg"}, "JPEG & GIF Images") 
 *     chooser.addChoosableFileFilter(filter); 
 *     chooser.showOpenDialog(this); 
 * 
 */  
public class ExtensionFileFilter extends FileFilter {  
/*    private static String TYPE_UNKNOWN = "Type Unknown";  
    private static String HIDDEN_FILE = "Hidden File";*/  
    private Hashtable<String, ExtensionFileFilter> filters = null;  
    private String description = null;  
    private String fullDescription = null;  
    private boolean useExtensionsInDescription = true;  
    /** 
     * Creates a file filter. If no filters are added, then all 
     * files are accepted. 
     * 
     * @see #addExtension 
     */  
    public ExtensionFileFilter() {  
    	this.filters = new Hashtable<String, ExtensionFileFilter>();  
    }  
    /** 
     * Creates a file filter that accepts files with the given extension. 
     * Example: new ExampleFileFilter("jpg"); 
     * 
     * @see #addExtension 
     */  
    public ExtensionFileFilter(String extension) {  
    	this(extension,null);  
    }  
    /** 
     * Creates a file filter that accepts the given file type. 
     * Example: new ExampleFileFilter("jpg", "JPEG Image Images"); 
     * 
     * Note that the "." before the extension is not needed. If 
     * provided, it will be ignored. 
     * 
     * @see #addExtension 
     */  
    public ExtensionFileFilter(String extension, String description) {  
    	this();  
    	if(extension!=null) addExtension(extension);  
    	if(description!=null) setDescription(description);  
    }  
    /** 
     * Creates a file filter from the given string array. 
     * Example: new ExampleFileFilter(String {"gif", "jpg"}); 
     * 
     * Note that the "." before the extension is not needed adn 
     * will be ignored. 
     * 
     * @see #addExtension 
     */  
    public ExtensionFileFilter(String[] filters) {  
    	this(filters, null);  
    }  
    /** 
     * Creates a file filter from the given string array and description. 
     * Example: new ExampleFileFilter(String {"gif", "jpg"}, "Gif and JPG Images"); 
     * 
     * Note that the "." before the extension is not needed and will be ignored. 
     * 
     * @see #addExtension 
     */  
    public ExtensionFileFilter(String[] filters, String description) {  
    	this();  
    	for (int i = 0; i < filters.length; i++) {  
    		// 	add filters one by one  
    		addExtension(filters[i]);  
    	}  
    	if(description!=null) setDescription(description);  
    }  
    /** 
     * Return true if this file should be shown in the directory pane, 
     * false if it shouldn't. 
     * 
     * Files that begin with "." are ignored. 
     * 
     * @see #getExtension 
     * @see FileFilter#accepts 
     */  
    public boolean accept(File f) {  
    	if(f != null) {  
    		if(f.isDirectory()) {  
    			return true;  
    		}  
    		String extension = getExtension(f);  
    		if(extension != null && filters.get(getExtension(f)) != null) {  
    			return true;  
    		};  
    	}  
    	return false;  
    }  
    /** 
     * Return the extension portion of the file's name . 
     * 
     * @see #getExtension 
     * @see FileFilter#accept 
     */  
     public String getExtension(File f) {  
    	 if(f != null) {  
    		 String filename = f.getName();  
    		 int i = filename.lastIndexOf('.');  
    		 if(i>0 && i<filename.length()-1) {  
    			 return filename.substring(i+1).toLowerCase();  
    		 };  
    	 }  
    	 return null;  
    }  
    /** 
     * Adds a filetype "dot" extension to filter against. 
     * 
     * For example: the following code will create a filter that filters 
     * out all files except those that end in ".jpg" and ".tif": 
     * 
     *   ExampleFileFilter filter = new ExampleFileFilter(); 
     *   filter.addExtension("jpg"); 
     *   filter.addExtension("tif"); 
     * 
     * Note that the "." before the extension is not needed and will be ignored. 
     */  
    public void addExtension(String extension) {  
    	if(filters == null) {  
    		filters = new Hashtable<String, ExtensionFileFilter>(5);  
    	}  
    	filters.put(extension.toLowerCase(), this);  
    	fullDescription = null;  
    }  
  
    /** 
     * Returns the human readable description of this filter. For 
     * example: "JPEG and GIF Image Files (*.jpg, *.gif)" 
     * 
     * @see setDescription 
     * @see setExtensionListInDescription 
     * @see isExtensionListInDescription 
     * @see FileFilter#getDescription 
     */  
    public String getDescription() {  
    	if(fullDescription == null) {  
    		if(description == null || isExtensionListInDescription()) {  
    			fullDescription = description==null ? "(" : description + " (";  
    			// build the description from the extension list  
    			Enumeration<String> extensions = filters.keys();  
    			if(extensions != null) {  
    				fullDescription += "." + (String) extensions.nextElement();  
    				while (extensions.hasMoreElements()) {  
    					fullDescription += ", " + (String) extensions.nextElement();  
    				}  
    			}  
    			fullDescription += ")";  
    		} else {  
    			fullDescription = description;  
    		}  
    	}  
    	return fullDescription;  
	}  
    /** 
     * Sets the human readable description of this filter. For 
     * example: filter.setDescription("Gif and JPG Images"); 
     * 
     * @see setDescription 
     * @see setExtensionListInDescription 
     * @see isExtensionListInDescription 
     */  
    public void setDescription(String description) {  
    	this.description = description;  
    	fullDescription = null;  
    }  
    /** 
     * Determines whether the extension list (.jpg, .gif, etc) should 
     * show up in the human readable description. 
     * 
     * Only relevent if a description was provided in the constructor 
     * or using setDescription(); 
     * 
     * @see getDescription 
     * @see setDescription 
     * @see isExtensionListInDescription 
     */  
    public void setExtensionListInDescription(boolean b) {  
    	useExtensionsInDescription = b;  
    	fullDescription = null;  
    }  
    /** 
     * Returns whether the extension list (.jpg, .gif, etc) should 
     * show up in the human readable description. 
     * 
     * Only relevent if a description was provided in the constructor 
     * or using setDescription(); 
     * 
     * @see getDescription 
     * @see setDescription 
     * @see setExtensionListInDescription 
     */  
    public boolean isExtensionListInDescription() {  
    	return useExtensionsInDescription;  
    }  
}